• Korean Journal of Environmental Biology
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• v.36 no.4
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• pp.538-543
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• 2018

Powdery mildew caused by Podosphaera xanthii is a disease in cucurbit crops especially in green house. The objective of this study was to determine the effect of alternative fungicide spraying system for control of powdery mildew disease. We selected four fungicides with different mode of action and made three treatment combinations of each fungicide in 2017. Pyraclostrobin-flutianyl-penthiopyrad treatment showed the highest control value (87%) while, pyraclostrobin-pyraclostrobin-pyraclostrobin treatment showed the lowest control value (32.5%). So it seemed like the treatment was not suitable for control of powdery mildew. In 2018, pyraclostrobin of pyraclostrobin-flutianyl-penthiopyrad was replaced to contact fungicide called iminoctadine-tris-albesilate and compared control effect of two treatments. Two of the treatments showed similar control value (87.0% for pyraclostrobin, 89.0% for iminoctadine-tris-albesilate). These two tests in 2017 and 2018 indicated that alternative treatment of different fungicides is essential for controlling of powdery mildew and inhibiting development of fungicide resistance.

• Korean Journal Plant Pathology
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• v.2 no.1
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• pp.22-30
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• 1986

The effect of powdery mildew infection on the $^{14}CO_2$ assimilation and metabolism of $^{14}C-$assimilates was studied with spring barley cultivars, susceptible Peruvian and adult-plant resistant Asse at the four-leaf stage. No consistent differences between Peruvian and Asse were revealed in $^{14}CO_2$ assimilation and metabolism of $^{14}C-$assimilates in healthy whole plants. In the two cultivars, $^{14}CO_2$ assimilation and translocation of assimilates decreased as the number of infected leaves increased. Despite the same infection intensity, $^{14}CO_2$ assimilation was less inhibited in Asse than Peruvian. Infection reduced the fixation of $^{14}CO_2$ in noninfected fourth leaves of Peruvian more severely than that of Asse. Infection of the lower 3 leaves also inhibited the incorporation of 14 C into carbohydrates such as fructose and glucose in noninfected fourth leaves and their translocation into leaf sheathes, the inhibitions being greater in Peruvian than Asse. In the infected third leaves, there was a reduction of 14 C-activity in carbohydrates, more $^{14}C-$labeled fructose and glucose being retained in Peruvian. The stimulation of $^{14}C-$organic acid synthesis in all plant organs was more pronounced in Peruvian than Asse. Powdery mildew markedly increased the incorporation of $^{14}C$ into amino acids in infected third and noninfected fourth leaves, but reduced their translocation to the leaf sheathes. A greater rise of $^{14}C-$ activity in some amino acids in the two leaves was found in Peruvian than Asse.

• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.552-555
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• 2009

A new standard rose cultivar "Snow Day" was bred from the cross between pink standard cultivar "Saphia" and pink standard cultivar "Bridal Beauty" at the National Institute of Horticulture & Herbal Science. The cross was made in 2003 and "Snow Day" was finally selected in 2008 after evaluating characteristics for three years from 2006 to 2008. A white standard cultivar, "Snow Day" grows vigorously and resistant to powder mildew. The major characteristics of this cultivar are $152stems/m^2/year$ in yield, 81.8 cm in length of cut flower, 11.3 cm in flower diameter, 29.2 in petal number, and 13.7 days in vase life. This cultivar can be propagated by both cutting and grafting. The consumer's preference for this cultivar is relatively higher than that for the control cultivar, "Tineke".

• Korean Journal of Plant Resources
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• v.11 no.3
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• pp.245-251
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• 1998

Test plants with 10 days old primary leaves were indouclated by shaking infected seedlings with sporulating colonies over them in an inoculation room under the conditions of 20$\pm$1 $^{\circ}C$ with constant illumination of 2.500 lux and 100% realtive humidity. A seeding reaction of 4 days after inoculation appreared in the trisomic types as opposed to Tri-5B line had been symtoms of a fungus 3 days after inoculation. The infection types of 8 days after inoculation were recognized with higher susceptibility to each trisomics in A genomie than B-genome. Tri-2A line showed less condium and there appeared symptoms of a conditions of mottle and formed papilla, and haustorium was not formed. However, Tri-5B line had much condium one overall leaves and showed a symtom like necrosis compared with normal plant. Moreover, Tri-5B line showed high sensitivity and high germination number of condium. These results inferred that resistant gene located on 2A chromosome and susceptibility gene is located on the chromosome 5B.

• The Korean Journal of Pesticide Science
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• v.5 no.3
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• pp.18-25
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• 2001

Ethanol extracts from 46 plants were tested for their fungicidal activity against six plant diseases consisting of Maynaporthe grisea, Rhizoctonia solani, Botrytis cinerea, Phytophthora infestans, Puccinia recondita, and Erysiphe graminis in the greenhouse studies. Strong activity at 5 and 10 mg/pot was produced from the extracts of Helianthus annuus flowers and Zea mays leaves against P. grisea. In a test with B. cineara, extracts of H. annuus leaves, H. annuus flowers, Chrysanthmum coronarium var. spatiosum, Cucurbita moschata seeds, Lycopersicon esculentum, Z. mays, and Z. mays leaves had strong activities at 5 mg/pot. In a test with P. recondita, strong activity was obtained from the extracts of Capsicum frutescens, C. moschata seeds, H. annuus seeds, L. esculentum, and Malva veticillata at 5 mg/pot. Against E. graminis, extracts of Cucumis sativus, H. annuus seeds, Salanum tuberosum, Z. mays, and Z. mays leaves produced strong activities at 10 mg/pot. All the extracts were ineffective against P. infestans and R. solani. Among seven extracts tested, the extracts of H. annuus leaves and flowers were highly effective against all the strains of B. cinerea resistant to carbendazim, procymidone, and diethofencarb. Furthermore, potent fungicidal activity was produced from the extracts of C. coronarium var. spatiosum and C. moschata seeds against the SSR, SRR, and RSR strains of B. cinerea, and Z. mays and Z. mays leaves against SSR and RSR. Extract of L. esculentum showed very strong activity only against RRS of B. cinerea.

• Horticultural Science & Technology
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• v.29 no.2
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• pp.160-163
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• 2011

A new rose cultivar was bred by crossing the red-yellow standard cultivar 'Konfetti' and pink standard cultivar 'Laser' at the Chungcheongbuk-do Agriculture Research and Extension Services. The cross was completed in 2003, after varietal characteristics was tested for 3 years from 2005 to 2007, 'Suryeo' was finally selected in 2007 and registered on the grant of plant variety rights in 2009. The cultivar was developed for a standard-type cut flower with white-pink petals. 'Suryeo' produced 149 stems/$m^2$ in a year and had 64 petals per flower. This new cultivar needed 48 days to flower and showed 12 days vase life. The length of cut stem was about 78 cm, and the fresh weight of stem was 50 g. This cultivar showed high resistance against powdery mildew.

• FLOWER RESEARCH JOURNAL
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• v.17 no.3
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• pp.190-193
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• 2009

A new standard rose cultivar 'Happy Day' was bred from the cross between pink standard cultivar 'Vivaldi' and pink standard cultivar 'Medeo' at the National Institute of Horticulture & Herbal Science. The first cross was in 2003 and 'Happy Day' was finally selected in 2008 after investigating characteristics for three years from 2006 to 2008. 'Happy Day', a pink standard cultivar grows vigorously and has powder mildew resistance. The major characteristics of this cultivar are $160stems\;m^{-2}$ per year in yield, 79.2 cm in length of cut flower, 9.9 cm in flower diameter, 28.8 in mean petal number, and 11.8 days in vase life. This cultivar can be propagated by both cutting and grafting. The consumers' preference of this cultivar is relatively higher than that of control cultivar, 'Nobleless'.

• Research in Plant Disease
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• v.15 no.3
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• pp.187-192
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• 2009

Pepper powdery mildew, Leveillula taurica is one of the most important pathogens of pepper in the greenhouses and fields in Korea and is becoming a worldwide disease. These experiments were carried out to investigate the optimal germination, disease development conditions, disease incidence and effective inoculation methods of pepper powdery mildew. The incidence of powdery mildew was investigated throughout the country based on the major pepper growing areas in 2009. The average rate of infected leaves ranged from 15.3% to 81.8% in greenhouses and fields. Powdery mildew incidences were more severe in greenhouses than those of fields. The optimal temperature for conidial germination was $25^{\circ}C$ and showed the highest germination at 6 hs after treatment. The range of temperature for germination was $10^{\circ}C$ to $35^{\circ}C$. Temperature of greater than $30^{\circ}C$ and below $20^{\circ}C$ affected the abnormal germination and germ tube elongation. The optimal relative humidity for germination and germ tube elongation was 85% and germination increased as relative humidity increased. Disease development started 8 days after inoculation and showed the highest disease severity at 15 days in greenhouse and field regardless of varieties. Among three different inoculation methods tested the spore dropping method was better than touching with infected leaves and spraying with spore suspension. However, the method has limitation in mass inoculation due to the amount of time consumed.

• Korean Journal of Breeding Science
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• v.50 no.4
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• pp.497-503
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• 2018

A strawberry variety 'Arihyang' was derived as an artificial cross between 'Tochiotome' and 'Seolhyang' in 2014. The seedling and line selections were conducted from 2014 to 2015. Preliminary and advanced yield trials of '14-5-5,' which was the final selected line, were conducted from 2015 to 2017. 'Arihyang' is suitable for forced cultivation and has strong plant vigor, uniformly large-sized fruit, and a high yield compared to those of the check variety, 'Seolhyang' and 'Maehyang.' Especially, vitamin C was at a significant level, which was approximately 15% higher than that of 'Seolhyang.' The average number of flowers per first flower cluster was 10.5, which could reduce the labor of thinning fruit. Its fruit has a conical shape, dark red color, and glossy skin. The fruit was of good quality but has recommendations for harvest at the fully ripened stage. 'Arihyang' has intermediate resistant to phytophthora crown rot, but is susceptible to powdery mildew, gray mold, anthracnose, and fusarium wilt. It is reguired to manage major diseases and pests using optimum cultivation techniques and chemical control.

• FLOWER RESEARCH JOURNAL
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• v.19 no.3
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• pp.164-167
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• 2011

A new spray rose cultivar 'Glory Purple' was bred from the cross between a pink spray cultivar 'Macarena' and a pink spray cultivar 'Million Pink' at the National Institute of Horticulture & Herbal Science. The cross was made in 2004 and a candidate genotype which named as 'Glory Purple' was selected in 2009 after three years investigation for agronomical characters from 2007 to 2009. 'Glory Purple', a purple colored spray cultivar, has vigorous growth and has powdery mildew resistance. The major characteristics of this cultivar are high yield and long stem with relatively large flower size with $157stems/m^2/year$ in yield, 63.5 cm in mean length of cut flower, 6.8 cm in mean flower diameter, 25.78 in mean petal number, and 10.2 days in mean vase life. This cultivar is suitable for propagation by both cutting and grafting methods. The consumer's preference of this cultivar is relatively higher than that of the control cultivars, 'Pinky and Charming'.